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Arxiv: Reconstructing Cosmic History: JWST-Extended Mapping of the Hubble Flow from z \sim 0 to z \sim7.5 with HII Galaxies Published: 4/25/2024 3:11:27 AM Updated: 4/25/2024 3:11:27 AM

Paper abstract: Over twenty years ago, Type Ia Supernovae (SNIa) [arXiv:astro-ph/9805201,arXiv:astro-ph/9812133] observations revealed an accelerating Universeexpansion, suggesting a significant dark energy presence, often modelled as acosmological constant, \Lambda. Despite its pivotal role in cosmology, thestandard \LambdaCDM model remains largely underexplored in the redshift rangebetween distant SNIa and the Cosmic Microwave Background (CMB). This studyharnesses the James Webb Space Telescope's advanced capabilities to extend theHubble flow mapping across an unprecedented redshift range, from z ~ 0to z ~ 7.5. Utilising a dataset of 231 HII galaxies and extragalacticHII regions, we employ the \text{L}-\sigma relation, correlating theluminosity of Balmer lines with their velocity dispersion, to define acompetitive technique for measuring cosmic distances. This approach maps theUniverse's expansion over more than 12 billion years, covering 95\% of its age.Our analysis, using Bayesian inference, constrains the parameter space \lbraceh, \Omega_m, w_0\rbrace = \lbrace 0.731\pm0.039, 0.302^{+0.12}_{-0.069},-1.01^{+0.52}_{-0.29}\rbrace (statistical) for a flat Universe. These resultsprovide new insights into cosmic evolution and suggest uniformity in thephoto-kinematical properties of young massive ionizing clusters in giant HIIregions and HII galaxies across most of the Universe's history.